diff --git a/core/serialization/variables.js b/core/serialization/variables.js
index 1d4786c66..c1ae6dc60 100644
--- a/core/serialization/variables.js
+++ b/core/serialization/variables.js
@@ -26,7 +26,7 @@ const serializationRegistry = goog.require('Blockly.serialization.registry');
  * @typedef {{
  *   name: string,
  *   id: string,
- *   type: (string|undefined),
+ *   type: (string|undefined)
  * }}
  */
 var State;